update to version 3.1.0
* Include response headers in ClientExceptions
* Add copy object method
* Support client certificate/key
* Add new doc structure and contents for swiftclient
* Add --json option to `swift capabilities` / `swift info`
* Convert numeric and boolean header values to strings
* Correct doc string for http_conn argument
* authors/changelog updates for 3.1.0 release
* Add tests for thread option validation
* Drop *.dbm* before running tests
* fixing nit picks in python-swiftclient doc
* boolean logic cleanup in service.Swift[Copy|Post]Object
* Query string functionality for containers
* Check responses when retrying bodies
* Add python version constraint python>=2.7
* Use mock patch to handle get_auth_keystone
* Default to v3 auth if we find a (user|project)-domain-(name|id) option
* Initialise delete_object mock before it's called
* Accept gzip-encoded API responses
* Use application/directory content-type for dir markers
* Fix examples and missing code-block
* Strip leading/trailing whitespace from headers
* Move other-requirements.txt to bindep.txt
* Suppress InsecureRequestWarning when using --insecure
* reenable sidebar links
* Migrated contributing file from .md to .rst
* Fixed a typo in SwiftService API doc
* Move python-keystoneclient to "extras"
* Pull option processing out to service.py